1. Field of the Invention
This invention relates to a connector, and more particularly to a lock-equipped connector.
2. Description of the Related Art
Conventionally, there has been proposed a connector provided with an insulator (housing) and a front shell (see Japanese Patent Laid-Open Publication No. H08-273764 (paragraphs [0012] to [0017] and FIG. 1)).
The insulator is comprised of a body and an insertion portion. The body holds a plurality of contacts.
The insertion portion is generally plate-shaped, and is inserted into a receiving portion of a mating connector. Grooves are formed at respective laterally opposite ends of the insertion portion.
The front shell also serves as a locking member for locking the mating connector. The front shell is comprised of a front shell body, a pair of hooks, a connecting portion, and a movable piece. The front shell body covers the insulator. The pair of hooks each have a foremost end formed with an approximately triangular engaging nail that is hooked to the mating connector. The pair of hooks are arranged in the associated grooves of the insertion portion of the insulator except for the engaging nails. The engaging nails protrude from the associated grooves. The connecting portion joins the pair of hooks to each other. A protrusion is formed on a central part of the connecting portion. The movable piece has a spring section in the form of a plate. The movable piece has the connecting portion integrally formed therewith at one end thereof, and has the front shell body connected to the other end thereof. The movable piece is capable of bending in the direction of a plate thickness thereof. By bending the movable piece, it is possible to move the pair of hooks in the respective groves in the direction of thickness of the insertion portion.
The front shell is combined with a back shell to cover the whole insulator. The front shell and the back shell are covered with a hood. The hood includes a pressing portion. When the pressing portion is pressed, the protrusion of the connecting portion is pressed, whereby the respective engaging nails of the pair of hooks are withdrawn into the associated grooves (toward the bottom surfaces of the associated grooves).
When the insertion portion of the insulator of the connector is inserted into the receiving portion of the mating connector, the respective engaging nails of the pair of hooks are pushed into the associated grooves by the mating shell that covers the receiving portion.
When the insertion portion of the insulator is inserted into the receiving portion of the mating connector until the engaging nails of the hooks reach locking holes formed in the mating shell, the engaging nails are inserted into the locking holes of the mating shell by the spring force of the movable piece of the front shell. As a result, the connector is locked by the mating connector.
On the other hand, when the connector is to be removed from the mating connector, it is only required to press the pressing portion of the hood of the connector and pull the connector in the removing direction with the pressing portion pressed. When the pressing portion is pressed, the connecting portion is pressed via the protrusion to cause the engaging nails of the hooks to be moved away from the locking holes of the mating shell, and be withdrawn into the grooves. As a consequence, the mating connector is unlocked from the connector, thereby making it possible to remove the connector from the mating connector.
Recently, there is an increasing demand for making connectors compact in size. When a connector is made compact in size, the spring length of a spring section (movable piece of a front shell) of the connector is accordingly reduced.
However, to reliably maintain the connector in a state locked to a mating connector, engaging nails of hooks cannot be made too small in size. This means that there is hardly any change in the amount of motion of the engaging nails of the hooks (the amount of motion of the engaging nails in the direction of thickness of an insertion portion) when the connector is fitted to the mating connector.
Therefore, although the spring length of the spring section is reduced along with the reduction of the size of the connector, there is hardly any change in the amount of motion of the engaging nails of the hooks. This causes an increase in the amount of bending of the spring section, which can cause plastic deformation of the spring section.